/Engine/Source/Runtime/MovieScene/Public/MovieSceneCommonHelpers.h
Gather up descendant movie scene sub-sections from the incoming movie scene
static void GetDescendantSubSections ( const [UMovieScene](API\Runtime\MovieScene\UMovieScene) * InMovieScene, [TArray](API\Runtime\Core\Containers\TArray)< [UMovieSceneSubSection](API\Runtime\MovieScene\Sections\UMovieSceneSubSection) * > & InSubSections )